Species of North American Cybaeus L. Koch (Araneae: RTA clade: Cybaeidae) are common moist-forest spiders classified in Holarctic and Californian clades. Here, in the second paper in a planned series reviewing the six Californian clade species groups, we review the species of the aspenicolens group. We recognize five species in two subgroups: the aspenicolens subgroup (Cybaeus aspenicolens Chamberlin & Ivie, C. blasbes Chamberlin & Ivie, and C. coylei Bennett spec. nov.) and the fraxineus subgroup (C. fraxineus Bennett spec. nov. and C. thermydrinos Bennett). The species of the aspenicolens group have very restricted distributions on the western slopes of the central and southern Sierra Nevada mountain range from Tuolumne County south to northern Kern County in east central California, U.S.A. Descriptions, illustrations, distribution maps, and an identification key are provided for the five species as well as a discussion of conservation issues of relevance to the group.
